TY - JOUR
T1 - Distinguishing between buried semiconductor/metal contacts and hybrid semiconductor/metal/liquid contacts at n-GaAs/KOH-Se-/2-(aq) junctions
AU - Bansal, Ashish
AU - Tan, Ming X.
AU - Tufts, Bruce J.
AU - Lewis, Nathan S.
PY - 1993
Y1 - 1993
N2 - The current-voltage properties of n-GaAs photoanodes have been evaluated in KOH-Se-/2-(aq), CH3CN-Fc+/0, and CH3CN-MV2+/+ solutions. Chemisorption of transition-metal ions (RhIII, CoIII, RuIII, OsIII) onto n-GaAs has been shown previously to effect improved photoanode behavior for n-GaAs/KOH-Se-/2-(aq) contacts, but it is not clear whether the chemisorbed metal forms a buried semiconductor/metal junction or results in a hybrid semiconductor/metal/liquid contact. After chemisorption of transition-metal ions, n-GaAs photoanodes displayed different open circuit voltages in contact with each electrolyte solution investigated. The role of the chemisorbed metal in the n-GaAs/M/KOH-Se-/2-(aq) system is, therefore, best described as catalyzing interfacial charge transfer at the semiconductor/liquid interface, as opposed to establishing a semiconductor/metal or semiconductor/ insulator/metal contact that is exposed to, but not influenced by, the electrolyte solution.
AB - The current-voltage properties of n-GaAs photoanodes have been evaluated in KOH-Se-/2-(aq), CH3CN-Fc+/0, and CH3CN-MV2+/+ solutions. Chemisorption of transition-metal ions (RhIII, CoIII, RuIII, OsIII) onto n-GaAs has been shown previously to effect improved photoanode behavior for n-GaAs/KOH-Se-/2-(aq) contacts, but it is not clear whether the chemisorbed metal forms a buried semiconductor/metal junction or results in a hybrid semiconductor/metal/liquid contact. After chemisorption of transition-metal ions, n-GaAs photoanodes displayed different open circuit voltages in contact with each electrolyte solution investigated. The role of the chemisorbed metal in the n-GaAs/M/KOH-Se-/2-(aq) system is, therefore, best described as catalyzing interfacial charge transfer at the semiconductor/liquid interface, as opposed to establishing a semiconductor/metal or semiconductor/ insulator/metal contact that is exposed to, but not influenced by, the electrolyte solution.
UR - http://www.scopus.com/inward/record.url?scp=0001638713&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001638713&partnerID=8YFLogxK
U2 - 10.1021/j100130a031
DO - 10.1021/j100130a031
M3 - Article
AN - SCOPUS:0001638713
VL - 97
SP - 7309
EP - 7315
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 28
ER -